SEL-311L Line Current Differential Protection and ...

Schweitzer Engineering Laboratories, Inc. SEL-311L Data Sheet

Differential Relays With Alpha Plane RestraintProvide Superior Security, Speed, and Sensitivity

Major Features and Benefits➤ Synchrophasors. Improve operator awareness of system conditions. Use real-time data to view load

angles, improve event analysis, and provide state measurements.

➤ Security and Reliability. Provide security for CT saturation and channel asymmetry by using thealpha plane restraint characteristic.

➤ Protection Sensitivity. Provide sensitivity without sacrificing security during external faults throughthe use of negative-sequence current differential and alpha plane restraint.

➤ Protection Speed. Subcycle operating times at only four times minimum pickup for phase elements.

➤ Single-Pole Tripping. Improve system stability with optional single-pole tripping by differential andZone 1 distance elements.

➤ Full-Featured Backup Protection. Standard backup protection includes: four zones of distance pro-tection, directional overcurrent elements, and a four-shot reclose logic system.

➤ Easy to Apply. Select CT ratios and channel ID and the relay is ready to be used on most differentialapplications. Use application settings for simplifying setting requirements.

➤ Communication Security. True hot standby communications for no loss or degradation in protectionduring single channel failure. Isolation of 1.5 kV on electronic differential communication circuits.IEEE C37.94 fiber to multiplexer compatible. Multiple channel paths do not require the same baud rateor channel delay.

➤ Three-Terminal Application. Apply the SEL-311L on three-terminal lines without compromisingprotection even on loss of a single differential channel.

➤ Mismatched CTs. Set the CT ratio for all connected terminals. The alpha plane restraint characteristicprevents misoperation due to mismatched characteristics such as voltage class or burden.

➤ Automation. Equip the SEL-311L with optional dual failover Ethernet communications for Telnet,FTP, read-only web server, and IEC 61850 communications support.

SEL-311L Line Current Differential Protection and Automation System

SEL-311L Data Sheet Schweitzer Engineering Laboratories, Inc.

2

Functional Overview

Figure 1 Functional Diagram

Protection FeaturesThe SEL-311L contains an advanced line current differ-ential system that is easy to set and apply, while still giv-ing subcycle operation and superior fault resistancecoverage. It is suitable for protection of any transmissionline or underground cable where digital communications,in the form of either a 56/64 kb channel or a dedicatedfiber-optic interface is available. Enable as many as fourzones of phase and ground mho distance backup ele-ments plus four zones of ground quadrilateral distanceelements. These distance elements, together with over-current functions, may be applied in communications-assisted and stepped-distance protection schemes (seeFigure 1).

Predefined configurations for typical applications areincluded in the relay settings. These configurations allowfor greatly reduced settings for many line configurations,with or without potential transformers.

Protection ElementsThe SEL-311L differential elements compare phase andsequence components from each line terminal, as illus-trated in Figure 2. Because line charging current has avery low negative-sequence component, negative-sequence current differential protection allows for high

sensitivity without compromising security. The phaseelements provide high-speed protection for severe or bal-anced faults. This allows high-speed operation evenunder heavy load flow conditions when system stabilitymay be critical.

The innovative differential protection in the SEL-311Lchecks the vector ratio of the local and remote currents in a complex plane, known as the alpha plane, asshown in Figure 3, Figure 4, Figure 6, and Figure 7. Forload and external faults, with no CT or communicationerrors, the vector ratio of remote current to local currentwill be –1 or 1∠180º. Errors introduced from CTs ornonequal communications path delays cause the ratio toappear at different locations within the complex ratioplane. The SEL-311L restraint characteristic improveson prior systems. The SEL-311L restraint regionsurrounds the ideal external fault and load current pointallowing for errors in both magnitude and phase angle.CT saturation, channel asymmetry, and other effectsduring faults outside the protected zone produce shifts inthe magnitude and angle of the ratio. The restraintcharacteristic provides proper restraint for theseconditions and still detects high-impedance faults and“outfeed” faults that occur within the protected zone. Therestraint region is adjustable both in angular extent andradial reach.

ANSI NUMBERS/ACRONYMS AND FUNCTIONS

21 Phase and Ground Distance

25 Synchronism Check

27/59 Under- and Overvoltage

50 Overcurrent

51 Time-Overcurrent

67 Directional Overcurrent

68 Out-of-Step Block/Trip

79 Single-and Three-Pole Reclosing

81 (O, U) Over- and Underfrequency

85 RIO SEL MIRRORED BITS Communications

DFR Event Reports

HMI Operator Interface

LGC SELOGIC Control Equations

MET High-Accuracy Metering

PMU Synchrophasors

SER Sequential Events Recorder

ADDITIONAL FUNCTIONS

BRM Breaker Wear Monitor

LDE Load Encroachment

LOC Fault Locator

SBM Station Battery Monitor

1 Copper or Fiber Optic * Optional Feature

59

27

3

3

5067

79

6887L 51

81OU

85RIOBRM DFR HMI LGC LOC PMU

SBM SER

Bus

1

SEL-311L

3

EIA-232

1

EIA-485

2

Ethernet*1

1

IRIG-B

21

25

IL( ) IR( )


3

The differential protection algorithms are insensitive toCT saturation effects due to different CT characteristicsat the line ends or remnant CT flux. This preventstripping on through faults and allows the use of existingCTs at each line end. The SEL-311L current connections

add very little burden, which allows line currentdifferential protection to be added to multiuse CTswithout degradation of accuracy (see Figure 5 andFigure 6).

Figure 2 Differential Element Operate and Restraint Regions

Figure 3 Operate andRestraint Regions in the Alpha Plane

For characteristics with the same sensitivity, SEL-311L Relays have greater security than percent-restraint, as seen in this alpha plane comparison.

Figure 4 Channel Asymmetry in the Alpha Plane

Communications channel asymmetry causes errors in angle and is easily handled by the SEL-311L semi-annular restraint characteristic. Percent-restraint is less secure.

Figure 5 Effect of CurrentTransformer Saturation in Wave FormSecondary CT currents resulting in false differential current due to CT saturation at one end of the protected line.

Figure 6 Effect of CurrentTransformer Saturation in Alpha Plane

For the CT saturation shown, the current ratio trajectory plots outside the percent-restraint circle while remaining securely inside the SEL-311L semi-annular restraint characteristic. Percent-restraint could misoperate for this fault.

SEL-311L SEL-311L

Differential Operate

Ia, Ib, Ic

DifferentialRestraint


ImIRIL

( (

ReIRIL

( (SEL-311L restraint semi-annulus characteristic

Percent-restraint plots as circle in Alpha plane

Alpha plane

Operate Region

-1

Alpha plane

0-60

-40

-20

0

20

40

60

80

Cycle

Wave

(am

pere

s)

4 6 8 10 12

Remote secondarycurrent with no

saturation for anexternal fault

Local secondarycurrent showingCT saturation foran external fault

0.1250.1880.25

0.313

0.3750.4380.50.5630.6250.6880.750.8130.8750.9381.061.131.196.566.63

6.696.756.816.886.9477.067.137.19

7.257.317.387.447.57.567.63

7.697.757.81

7.8888.068.138.198.258.5

8.568.638.69

8.75 8.818.88

9.639.699.759.819.889.9410.310.310.410.410.5

10.6 10.6

10.710.810.8

10.910.91111.111.111.211.311.411.511.611.611.711.811.811.9

Alpha plane


4

Figure 7 System Conditions in the Alpha Plane

Alpha Plane Restraint Provides Security, Even With CT SaturationThe SEL-311L restraint characteristic advances the stateof the art in transient security for differential relays. CTsaturation during external faults moves the remote tolocal current ratio plot in the alpha plane. The restraintcharacteristic accommodates a large degree of CT satura-tion.

The following equation gives the CT selection criteria fora two-terminal application:

150 ≥ (X/R + 1) • IF • ZB

where:➤ X/R is system X/R ratio➤ IF is secondary fault current, per unit of nominal

secondary current➤ ZB is CT burden, per unit of rated secondary

burden

To avoid CT saturation entirely, select and apply the CTsuch that

20 ≥ (X/R + 1) • IF • ZB

Notice that the SEL-311L remains secure even when theCT is over-burdened 7.5 times worse than the case whichavoids all CT saturation.

Sensitivity and High SpeedThe SEL-311L provides sensitive negative- and zero-sequence differential elements, as well as high-speedphase current differential elements. Set negative- andzero-sequence differential elements below load or linecharging current without risk of misoperation. The graphin Figure 9 shows the average operate time, includinghigh-speed outputs, for the phase differential units. Forimproved security on uneven pole operation, thesequence units operate approximately 2 cycles slower.

Figure 8 Ground Fault Sensitivity

Figure 9 Current Differential Element Trip Times

Single-Pole TrippingIn this example two-line system (Figure 10) we can lookat the stability curve to see the power transfer capabilityunder different system conditions. In cases where sys-tems must operate near stability limits, it is clear that theoptional single-pole tripping capability of the SEL-311Lwill improve the transient stability.

Figure 10 Single-Pole Tripping Diagram

Remote CTSaturation

Restraint Region

ReIRIL

Im

Load

IRIL

Local CT Saturation

( (

( (

Operate Region

Channel Asymmetry

RF(Ω sec.)

Load Current (Per Unit of Nominal)1/3

50

150

100

2/3 1

87L Speed

0.0

1.0

2.0

3.0

4.0

5.0

Time (

Cycle

s)

Phase

Difference Current (A)

Negative and Zero Sequence

1 5 10 50 60

Bus A Bus BLine W

Line Z


5

Figure 11 Equal Area Curve

Single-pole tripping improves stability as illustrated bythe difference between Area B (for single-pole trips) andArea B + C (for three-pole trips) (Figure 11). Thedifference in these two areas is the extra stabilizingmomentum available when single-pole tripping is used ascompared to three-pole tripping.

The high-speed tripping of the SEL-311L complementsthe single-pole tripping by minimizing the size ofArea A. The operating time of the SEL-311L, includingoutput time, is approximately 0.75 cycles for a severefault.

Full-Scheme and/or Current-Only Backup ProtectionFull-Scheme Backup ProtectionThe SEL-311L includes all of the protection elements inthe SEL-311C Relay. A complete and independent dis-tance and directional overcurrent system is included foruse if potential transformers are available (seeFigure 12). These elements run on a separate processorplatform using separate contacts and firmware. Failure ofeither the 87L channel or processing hardware does notaffect backup protection. Both step-distance and commu-

nications-assisted protection are available. Transmit thepermissive trip, direct trip, or block trip signal by usingthe current differential channel, MIRRORED BITS® com-munications on a separate serial port, or via contact tochannel equipment.

Backup protection maintains excellent sensitivity usingpatented Best Choice Ground Directional™ protection.All the features of the SEL-311C, such as load-encroachment, out-of-step, loss-of-potential detectionand blocking, and CCVT transient detection are alsoincluded.

Current-Only Backup ProtectionApply phase and ground overcurrent backup protectionelements in the SEL-311L. When the “Current-Only”Application Setting is used, these are the only backupelements that will be displayed for setting.

Three steps of phase and four steps of ground andnegative-sequence instantaneous/definite time-overcurrent protection are included. Inverse-time phase,ground, and negative-sequence overcurrent elements arealso included. If desired, backup elements can be enabledonly after a communications failure.

System Load Angle From A to B

Pow

er T

rans

fer

One Line Out of Service

Single-Phase Fault on Line

One Phase Tripped

Both Lines in Service

Area A

Area B

Area C

Area D


6

Figure 12 Full Scheme Backup Protection

SynchrophasorsThe SEL-311L now includes phasor measurement tech-nology that provides synchrophasor measurementsthroughout a power system. This technology in a protec-tive relay reduces or eliminates incremental installationand maintenance costs while leaving system reliabilityunaffected. Incorporate present and future synchrophasortechnology control applications without much effort intothe same devices that protect and control the power sys-tem.

High-Speed Trip ContactsInterrupt Trip CurrentSix high-speed, high-current interrupting contact outputsare controlled directly by the line current differentialprocessor. These contacts can interrupt trip currentsshould the breaker auxiliary contacts fail to open.Backup protection can use the same high-speed contactoutputs, passing backup trip decisions through thecurrent differential processor (see Figure 13).

Figure 13 Combined Distanceand Current Differential Protection

To maintain backup protection independent of linecurrent differential protection, use standard contacts(eight included) controlled by the backup protectionprocessor for backup tripping (see Figure 14).

Figure 14 Segregated Differential and Backup Tripping

SEL-311L SEL-311L

Differential Operate

Ia, Ib, Ic


POTT, DCB, etc.

Zone 1 / Direct Trip

Zone 2 / Permissive Zone

Zone 4 / Time Delay System Backup

Zone 3 /Blocking


SEL-311L

OUT201–OUT206

52a

52TC

+DC

–DC

TC

Backup87L

OUT201–OUT206

OUT101–OUT107

+DC

–DC

OUT201–OUT206

52a

52TCTC


7

Figure 15 Dual Channel Hot Standby Communications

Dual Channel,Hot Standby CommunicationsUse one or two current differential communicationschannels between the line ends. For a two-terminal line,the redundant channel is in hot standby mode until theprimary channel fails (see Figure 15). There is no inter-ruption of protection or delay in tripping, even if a faultoccurs simultaneously with the loss of one communica-tions channel (see Figure 16).

Figure 16 True Hot StandbyDual Communications and Dual Differential prevent loss or degradation of protection during channel failure.

The relay continuously monitors both channels forcorrect data transmission and channel delay. Channelquality reports available from the relay include short andlong term unavailability, and round trip channel delay.Use this information to accurately assess protection andcommunications system reliability and make appropriatechanges for maximum system reliability.

Channel RequirementsThe SEL-311L has options for the following channelinterfaces (select one or two):

➤ G.703 codirectional to multiplexer ➤ EIA-422 to multiplexer for a 64 kbps or 56 kbps

channel➤ 1300 nm single-mode (120 km) fiber➤ 1550 nm single-mode (120 km) fiber➤ IEEE C37.94-compatible multimode fiber to

multiplexer➤ IEEE C37.94-compatible modulated 1300nm sin-

gle-mode fiber to multiplexer

Figure 17 IEEE C37.94-Compatible

The SEL-311L Relay with an IEEE C37.94-compatible standard fiber interface. It provides a direct fiber-optic interface between the relay and multiplexer to prevent communication errors, equipment damage, and hazardous conditions due to ground potential rise.

=>>COMM Y L <Enter>SEL-311L Date: 05/26/01 Time: 09:27:03.269EXAMPLE: BUS B, BREAKER 3

FID=SEL-311L-R100-V0-Z001001-D20010625 CID=BAFDSummary for 87L Channel YChannel Status Alarms ROKY = 1 DBADY = 0 RBADY = 0 AVAY = 0

For 05/24/01 13:37:01.631 to 05/26/01 09:27:04.248

COMMUNICATION LOG SUMMARY COMMUNICATION STATISTICS # of Error records 29 Last error Data Error Data Error 20 Longest failure 4.685 sec. Dropout 9 Lost Packets, prev. 24 hours 407 Test Mode Entered 0 One Way Delay (Ping-Pong) 0.4 msec.

Error Recovery# Date Time Date Time Duration Cause 1 05/26/01 09:23:54.041 05/26/01 09:23:54.042 0.001 Data Error 2 05/26/01 09:23:53.888 05/26/01 09:23:54.040 0.152 Dropout Error 3 05/26/01 09:23:53.885 05/26/01 09:23:53.888 0.003 Data Error 4 05/26/01 09:23:53.882 05/26/01 09:23:53.885 0.003 Dropout Error . . . 27 05/24/01 13:37:04.688 05/24/01 13:37:04.689 0.001 Data Error 28 05/24/01 13:37:00.003 05/24/01 13:37:04.688 4.685 Dropout Error 29 05/24/01 13:37:00.000 05/24/01 13:37:00.003 0.003 Data Error

=>>

Figure 18 COMM Command Report

The SEL-311L Relay communications monitor reports performance of all 87L channels and MIRRORED BITS communications channels. Review these reports to optimize communications.

SEL-311L SEL-311LIa, Ib, Ic

Primary Channel

Ia, Ib, Ic

Hot Standby Channel

IR Channel X

IR Channel Y

Align andFilter

Align andFilter

87LSwitch

Operate

87L

ChannelMonitor

SEL-311L Multiplexer

RelayBuilding

CommunicationsBuilding

CommunicatesCurrents

Optical Fiber Link


8

Tapped Load ApplicationThe SEL-311L coordinates with tapped loads. A differ-ence-current ANSI or IEC overcurrent protection curve,as shown in Figure 19, coordinates with the tapped loadprotection. This prevents loss of the line for cases of afault on the tap, while still providing differential mea-surements of the protected line to give the fastest opera-tion possible. Implement either fuse-saving or trip-saving

schemes. For example, select high-speed, sensitive pro-tection for the initial shot and then delayed tripping on asubsequent reclose operation to allow a fuse on thetapped line to blow if the fault is still present. This can bemodified to accommodate the user's operation practicesand provide the best possible service for the end custom-ers. This feature is applicable to two- and three-terminallines.

Figure 19 Tapped Load Coordination

Relays determine current at the tap point. Overcurrent elements use that current to coordinate with tap protection. Use phase current, negative-sequence current, and zero-sequence current for optimal protection.

Three-Terminal LinesThe SEL-311L protects three-terminal lines in either apeer-to-peer configuration by using two channels con-nected to each relay, as shown in Figure 20, or in aleader-remote arrangement when only one relay is con-nected to two channels. The leader relay has line currentinformation from all terminals. It sends a trip signal tothe remote units when it determines there is a fault on theline.

ReclosingThe SEL-311L includes a four-shot recloser. Internal ele-ment status or external inputs can condition the recloserto match your practice:

➤ Reclose initiate (e.g., breaker status, fault type,trip).

➤ Drive-to-lockout or last shot (e.g., input from man-ual or SCADA open).

➤ Skip shot (use 27/59 elements, fault current magni-tude).

➤ Stall open-interval timing.➤ Separate times to reset from cycle or lockout.

The recloser shot counter can control which protectiveelements are used in each reclose interval for fuse-savingor fuse-coordination of tapped or downstream loads.Front-panel LEDs track the recloser state: Reset (RS) andLockout (LO).

SEL-311L SEL-311L

Tapped Load

Time

IT

IT

Relay Characteristic

Fuse Curve


9

Figure 20 Three-Terminal Line Protection Communications Connections

Bus Stub LogicBus stub protection is enabled by input or SELOGIC

control equation.➤ No analog data are sent to the remote terminal➤ Analog data received from the remote terminal are

ignored➤ Differential transfer trips are disabled

Figure 21 Automatic Bus Stub Protection

Fault LocatorIf potentials are applied, the SEL-311L provides an accu-rate fault location calculation even during periods of sub-stantial load flow. The fault locator uses fault type,replica line impedance settings, and fault conditions tocalculate fault location without communications chan-nels, special instrument transformers, or pre-fault infor-mation. This feature contributes to efficient dispatch ofline crews and fast restoration of service.

The relay provides fault location information on the frontpanel, in the event reports, and in event summaries.

Six Independent Setting GroupsThe relay stores six groups of settings. Select the activesetting group by contact input, serial port or front-panelcommand, or other programmable conditions. Use thesesetting groups to cover a wide range of protection andcontrol contingencies. Selectable setting groups make theSEL-311L ideal for applications requiring frequent set-ting changes and for adapting the protection to changingsystem conditions. Selecting a group also selects logicsettings.

Program group selection logic to adjust settings fordifferent operating conditions, such as stationmaintenance, seasonal operations, emergencycontingencies, loading, source changes, and adjacentrelay setting changes.

SEL-311L SEL-311L

SEL-311LOptional Channel

SEL-311LBus Stub Protected Line

Disconnect Switch


10

Relay and Logic Settings Software

Figure 22 QuickSet Screen

The ACSELERATOR QuickSet® SEL-5030 Softwareprogram uses the Microsoft Windows operating systemto simplify settings and provide analysis support for theSEL-311L.

Use QuickSet to create and manage relay settings:➤ Develop settings off-line with an intelligent set-

tings editor that only allows valid settings.➤ Create SELOGIC control equations with a drag and

drop graphical editor and/or text editor.➤ Use on-line help to assist with configuring proper

settings.➤ Organize settings with the relay database manager.➤ Load and retrieve settings by using a simple PC

communications link.

Use QuickSet to verify settings and analyze events:➤ Use the logic simulator to test setting schemes with

user or event report input stimulus. (Use for train-ing, too!)

➤ Analyze power system events with the integratedwaveform and harmonic analysis tools.

Use QuickSet to aid with monitoring, commissioning,and testing the SEL-311L:

➤ Use the HMI to monitor meter data, Relay Wordbits, and output contacts status during testing.

Use the PC interface to remotely retrieve breaker wear,voltage sag/swell/interruption reports, and other powersystem data.


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Metering and Monitoring

Advanced Metering CapabilitiesThe SEL-311L provides extensive metering capabilities,as shown in Table 1. Metering accuracies are provided inthe Specifications on page 1.23. Metering information isdisplayed on the relay front panel or is available via com-munications over the serial port.

Use the current differential meter to verify line chargingcurrent. Compare local and remote currents to detect CTconnection errors or CT ratio setting errors at anyterminal.

If voltages are supplied to the relay, power and energyquantities are also available.

Event Reporting and SEREvent Reports and Sequential Events Recorder (SER)simplify post-fault analysis and improve understandingof simple and complex protective scheme operations.They also aid in testing and troubleshooting relay set-tings and protection schemes.

Eleven 60-cycle, twenty-two 30-cycle, or forty-one15-cycle oscillographic event reports provide 4 or 16samples per cycle resolution for remote and differentialphase currents, each local analog channel, systemfrequency, dc system voltage, contact I/O, and manyrelay elements. Use the local and remote currentoscillography to completely reconstruct complex systemdisturbances, and check local and remote CTconnections during commission testing from a singlereport (see Figure 23).

Figure 23 Three-Terminal Oscillograph From Any Terminal

The SEL-311L SER records the last 512 event entries,which may include contact inputs, internal relayconditions, relay setting changes, and relay power-up.

The IRIG-B time-code input synchronizes the SEL-311LRelay SER time stamps to within ±5 ms of the time-source input. A convenient source for this time code isthe SEL-2032, SEL-2030, or SEL-2020Communications Processor (via Serial Port 2 on theSEL-311L). Line current differential protection does notrely on IRIG-B time synchronization, nor on any otherexternal source of time synchronization.

To simplify event analysis following an operation, relaysettings are appended to the bottom of each event report.

Table 1 Metering Capabilities

Quantities Description

Currents (local) IA, B, C, pol, I1, 3I2, 3I0 Individual phase, polarizing, and sequence currents for local relay terminal.

Currents (remote and difference) IA, B, C, I1, 3I2, 3I0 Individual phase and sequence currents for remote relay terminal and difference currents.

Voltages VA, B, C, S, V0, V1, V2 Individual phase voltages for wye-connected PTs, and positive-, negative-, and zero-sequence voltages.

Power MWA, B, C, 3P, MVARA, B, C, 3P Single-phase and three-phase MW and MVAR available for wye-connected PTs.

Energy MWhA, B, C, 3P, MVARhA, B, C, 3P Single-phase and three-phase MW and MVARh available for wye-connected PTs.

Power Factor PFA, B, C, 3P Single-phase and three-phase power factor; leading or lagging.

IL

IFIY

IX


12

Flexible Event AnalysisExamine line currents from two or three line ends in thesame event report. Use the SEL-5601-2 SYNCHRO-WAVE® Event Software to help visualize power systemdisturbances.

Event SummaryEach time the relay generates a standard event report, italso generates a corresponding Event Summary (seeFigure 24). This is a concise description of an event thatincludes the following information:

➤ Pre-fault and fault, local and remote phase, zero-and negative-sequence currents

➤ Status of each 87L channel➤ Phase voltages➤ Fault type at the time of the trip➤ System frequency at the time of the trigger➤ Recloser shot count at the time of the trigger➤ Relay identification➤ Event date and time➤ Event type➤ Fault location➤ ALARM status➤ Status of all MIRRORED BITS and 87L channels➤ Trip and close time tags➤ Breaker status (open/close)

Figure 24 Example Event Report Summary

The relay automatically sends an Event Summary to allserial ports set as “AUTO” each time an event report istriggered.

The relay gives each Event Summary a unique identifier.This allows an automated event system, such as theSEL-5040, to acknowledge triggered events, and toretrieve the associated oscillographic report reliably.

Synchrophasor MeasurementsUpgrade System ModelsSend synchrophasor data by using SEL Fast Messageprotocol to SEL communications processors, or toSEL-5077 SYNCHROWAVE Server phasor data concentra-tion software, or to an SEL-3306 Synchrophasor Proces-sor. Data rates of as much as one message per secondwith an accuracy of ±1 electrical degree provide for real-time visualization.

The SEL-5077 SYNCHROWAVE Server software and theSEL-3306 Synchrophasor Processor time correlate datafrom multiple SEL-311 relays and other phasormeasurement and control units (PMCUs). Then, theSEL-5077 sends the concentrated data to visualizationtools, such as the SEL-5078-2 SYNCHROWAVE CentralVisualization and Analysis Software, for use by utilityoperations.

Use SEL-2032 or SEL-2030 CommunicationsProcessors to collect synchrophasor data from multipleSEL-311 relays and incorporate the data into traditionalSCADA and EMS systems. Traditional power systemmodels are created based on measurements of voltagesand power flows at different points on the system. Thesystem state is then estimated based on a scan of thesevalues and an iterative calculation. The state estimationincludes an inherent error caused by measurementinaccuracies, time delays between measurements, andmodel simplifications. Synchrophasor measurementsreduce error and change state estimation into statemeasurement. The time required for iterative calculationis minimized, and system state values can be directlydisplayed to system operators and engineers.

Figure 25 Synchrophasor Measurements Turn State Estimation Into State Measurement

Improve Situational AwarenessProvide improved information to system operators.Advanced synchrophasor-based tools provide a real-timeview of system conditions. Use system trends, alarmpoints, and preprogrammed responses to help operatorsprevent a cascading system collapse and maximize sys-tem stability. Awareness of system trends provides opera-tors with an understanding of future values based onmeasured data.

δ1

δ2

V1

V2

V1

V2

P12

Q12

= h (V,θ)

State

= h (V,θ) + error

State

MeasurementsMeasurements

1 Second10 Minutes


13

Figure 26 Visualization of Phase Angle Measurements Across a Power System

➤ Increase system loading while maintaining ade-quate stability margins.

➤ Improve operator response to system contingenciessuch as overload conditions, transmission outages,or generator shutdown.

➤ Advance system knowledge with correlated eventreporting and real-time system visualization.

➤ Validate planning studies to improve system loadbalance and station optimization.

Figure 27 SYNCHROWAVE Central Real-Time Wide-Area Visualization Tool

IEC 61850 Communications (SEL-311L-1 and SEL-311L-7)IEC 61850 Ethernet-based communications provideinteroperability between intelligent devices within thesubstation. Logical nodes using IEC 61850 communica-tions allow standardized interconnection of intelligentdevices from different manufacturers for monitoring andcontrol of the substation. Reduce wiring between variousmanufacturers’ devices and simplify operating logic withSEL-311L relays equipped with IEC 61850. Eliminatesystem RTUs by streaming monitoring and control infor-mation from the intelligent devices directly to remoteSCADA client devices.

The SEL-311L-1 or SEL-311L-7 can be ordered withembedded IEC 61850 communications operating on dualfailover 100 Mbps Ethernet interfaces. Use IEC 61850communications for relay monitoring and controlfunctions, including:

➤ As many as 16 incoming GOOSE messages. Theincoming GOOSE messages can be used to controlas many as 32 control bits in the relay with <10 mslatency from device to device. These messagesprovide binary control inputs to the relay for high-speed control functions and monitoring.

➤ As many as eight outgoing GOOSE messages.Outgoing GOOSE messages can be configured forBoolean or analog data. Boolean data are providedwith <10 ms latency from device to device. Useoutgoing GOOSE messages for high-speed controland monitoring of external breakers, switches andother devices.

➤ IEC 61850 Data Server. SEL-311L relaysequipped with embedded IEC 61850 communica-tions provide data according to predefined logicalnode objects. As many as six simultaneous clientassociations are supported by each relay. RelevantRelay Word bits are available within the logicalnode data, so status of relay elements, inputs, out-puts, or SELOGIC control equations can be moni-tored using the IEC 61850 data server provided inthe relay.


14

Use the ACSELERATOR Architect® SEL-5032 Softwareto manage the logical node data for all IEC 68150devices on the network. This Microsoft Windows-basedsoftware provides easy-to-use displays for identifyingand binding IEC 61850 network data between logicalnodes using IEC 61850-compliant CID (Configured IEDDescription) files. CID files are used by Architect todescribe the data that will be provided by the IEC 61850logical node within each relay.

Telnet, FTP, and Read-Only Web Server

Order the SEL-311L-1 or the SEL-311L-7 with Ethernetcommunications and use the built-in Telnet and FTP(File Transfer Protocol) that come standard with Ethernetto enhance relay communication sessions. Use Telnet toaccess relay settings, metering, and event reportsremotely using the ASCII interface. Upload IEC 61850CID files to the relay via the high-speed Ethernet portusing FTP.

Enable the integrated read-only web server and browsethe relay with any standard web browser to safely readsettings, verify relay self-test status, inspect meterreports, read relay configuration, and more. The webserver allows no control or modification actions, so userscan be confident that an inadvertent button press willhave no adverse effects.

Substation Battery Monitor for DC Quality AssuranceThe SEL-311L measures and reports the substation bat-tery voltage presented to its power supply terminals. Therelay includes two programmable threshold comparatorsand associated logic for alarm and control. For example,if the battery charger fails and the measured dc voltagefalls below a programmable threshold, operations per-sonnel are then notified before the substation batteryvoltage falls to unacceptable levels. Monitor thesethresholds with the SEL Communications Processor. Usethe SEL Communications Processor to trigger messages,initiate telephone calls, or take other actions.

The measured dc voltage is reported in the METER displayvia serial port communications, on the LCD, and in theevent report. Use the event report data to see anoscillographic display of the battery voltage. You can seehow the substation battery voltage drops during trip,close, and other control operations.

Breaker Monitor Feature Allows for Intelligent Breaker Maintenance SchedulingCircuit breakers experience mechanical and electricalwear every time they operate. Effective scheduling ofbreaker maintenance takes into account the manufac-turer’s published data of contact wear versus interruptionlevels and operation count. The SEL-311L breakermonitor feature compares the breaker manufacturer’spublished data to the interrupted current.

Every time the breaker trips, the interrupted current isadded to its previous value. When the result of thisaddition exceeds the threshold set by the breaker wearcurve (Figure 28), the relay can alarm via serial port,output contact, or the front-panel display. With thisinformation, breaker maintenance is scheduled in atimely, economical fashion.

Figure 28 Breaker Contact Wear Curve and Settings

AutomationFlexible Control Logic and Integration FeaturesUse the SEL-311L control logic to:

➤ Replace traditional panel control switches.➤ Replace traditional indicating panel lights.➤ Replace traditional latching relays.➤ Eliminate RTU-to-relay wiring.

Eliminate traditional panel control switches with 16 localcontrol switches. Set, clear, or pulse local controlswitches with the front-panel pushbuttons and display.

Program the local control switches into your controlscheme via SELOGIC control equations. Use the localcontrol switches to trip test, enable/disable reclosing,trip/close the breaker, etc.

Eliminate RTU-to-relay wiring with 16 remote controlswitches. Set, clear, or pulse remote control switches viaserial port commands. Program the remote controlswitches into your control scheme via SELOGIC controlequations. Use remote control switches for SCADA-typecontrol operations: trip, close, settings group selection,etc.

kA Interrupted

(Set Point 1)

(Set Point 2)

(Set Point 3)

Breaker Manufacturer'sMaintenance Curve

Clos

e to

Ope

n Op

erat

ions


15

Replace traditional latching relays for such functions as“remote control enable” with 16 latching controlswitches. Program latch set and latch reset conditionswith SELOGIC control equations. Set or reset the latchcontrol switches via optoisolated inputs, remote bits,local bits, or any programmable logic condition. Thelatch control switches retain their state when the relayloses power.

Replace traditional indicating panel lights with 16programmable displays. Define custom messages (e.g.,REMOTE BREAKER OPEN, REMOTE BREAKER CLOSED,RECLOSER ENABLED) to report power system or relayconditions on the LCD. Control which messages aredisplayed via SELOGIC control equations by using anylogic point in the relay.

Serial Communications

Figure 29 Example Communication System

Three EIA-232 serial ports and one isolated EIA-485serial port each operate independently of the other serialports.

➤ Full access to event history, relay status, and meterinformation from the serial ports.

➤ Settings and group switching have password con-trol.

➤ DNP3 Level 2 protocol with point mapping(optional).

➤ Open communications protocols (see Table 2).

The relay does not require special communicationssoftware. ASCII terminals, printing terminals, or acomputer supplied with terminal emulation and a serialcommunications port is all that is required. SELmanufactures a variety of standard cables for connectingthis and other relays to a variety of external devices.Consult your SEL representative for more information oncable availability.

Relay-to-Relay Digital Communications (MIRRORED BITS)In addition to the differential channels, the SEL-311Lincludes MIRRORED BITS communications which canoperate simultaneously on any two serial ports for three-

terminal operation. The SEL patented MIRRORED BITS

technology provides bidirectional relay-to-relay digitalcommunications (see Figure 30).

SEL Communications Processor

SEL-311L

SEL-321SEL-311C

SEL-311L

ASCII Reports PlusInterleaved Binary Data

Dial-Up ASCII Link DNP SCADA Link

Table 2 Open Communications Protocols

Type Description

Simple ASCII Plain language commands for human and simple machine communications. Use for metering, setting, self-test status, event reporting, and other functions.

Compressed ASCII Comma-delimited ASCII data reports. Allows external devices to obtain relay data in an appropriate format for direct import into spreadsheets and database programs. Data are checksum protected.

Extended Fast Meter, Fast Operate, and Fast SER

Binary protocol for machine-to-machine communications. Quickly updates SEL-2032/2030/2020, RTUs, and other substation devices with metering information, relay element, I/O status, time-tags, open and close commands, summary event reports, and Sequence of Events records. Data are checksum protected.

Binary and ASCII protocols operate simultaneously over the same communications lines so control operator metering information is not lost while transferring an event report.

Distributed Port Switch Protocol Enables multiple SEL devices to share a common communications bus (two-character address setting range is 01–99). Use this protocol for low-cost, port-switching applications.

DNP3 Level 2 Slave Certified Distributed Network Protocol. Includes capability for settings-based DNP events, full-point remapping, individual scaling and deadband thresholds for analog inputs.

IEC 61850 Ethernet-based international standard for interoperability between intelligent devices in a substation.


16

This bidirectional digital communication creates eightadditional outputs (transmitted MIRRORED BITS) andeight additional inputs (received MIRRORED BITS) foreach serial port operating in the MIRRORED BITS mode.These MIRRORED BITS can be used to transferinformation between line terminals to enhancecoordination and achieve faster tripping or to provideadditional contact I/O with the SEL-2505. MIRRORED

BITS also help reduce total pilot scheme operating timeby eliminating the need to close output contacts anddebounce contact inputs. Use the dual-port MIRRORED

BITS capabilities for high-speed communications-assisted schemes applied to three-terminal transmissionlines.

Advanced SELOGIC Control EquationsAdvanced SELOGIC control equations put relay logic inthe hands of the protection engineer. Assign the relayinputs to suit your application, logically combineselected relay elements for various control functions, andassign outputs to your logic functions.

Programming SELOGIC control equations consists ofcombining relay elements, inputs, and outputs withSELOGIC control equation operators. Any element in theRelay Word can be used in these equations.

The SELOGIC control equation operators include thefollowing: OR, AND, invert, parentheses, and rising andfalling edges of element state changes.

In addition to Boolean-type logic, 16 general-purposeSELOGIC control equation timers eliminate externaltimers for custom protection or control schemes. Eachtimer has independent time-delay pickup and dropoutsettings. Program each timer input with any desiredelement (e.g., time-qualify a voltage element). Assignthe timer output to trip logic, reclose logic, or othercontrol scheme logic.

Figure 30 Integral MIRRORED BITS Communications Provides Secure Protection, Monitoring, and Control

Figure 31 Status and Trip Target LEDs, Front-Panel Display, and Pushbuttons

Fiber-Optic Cable

Bus 1 Bus 2

TXRX

1

TXRX

SEL-311L

Transmission Line

2

SEL-311L

SEL-28XX SEL-28XXOtherRelays

OtherRelays


17

Front-Panel User InterfaceStatus and Trip Target LEDs, Front-Panel Display, and Pushbuttons

Figure 31 shows a close-up view of the user interfaceportion of the SEL-311L front panel. It includes atwo-line, 16-character LCD, 16 LED status and targetindicators, and 8 pushbuttons for local communication.Table 3 explains the front-panel LEDs.

The LCD shows event, metering, setting, and relayself-test status information and allows relay settingschanges without the need for a data terminal.

The LCD is controlled by the pushbuttons, automaticmessages the relay generates, and user-programmedDisplay Points. The default display scrolls through anyactive, nonblank Display Points. If none are active, therelay scrolls through four two-line displays of the A-, B-,and C-phase local and remote currents in primaryquantities. Each display remains for two seconds, beforescrolling continues. Any message generated by the relaydue to an alarm condition takes precedence over thenormal default display. The EXIT pushbutton returns thedisplay to the default display, if some other front-panelfunction is being performed.

Error messages such as self-test failures are displayed onthe LCD in place of the default display when they occur.

Contact Inputs and OutputsThe SEL-311L includes six high-speed/high-interruptingoutputs as well as eight standard duty output contacts andsix optoisolated inputs. Assign the contact inputs forcontrol functions, monitoring logic, and general indica-tion. Except for a dedicated alarm output, each contactoutput is programmable using SELOGIC control equa-tions.

Table 3 Description of Target LEDs

Target LED Function

EN Relay powered properly and self-tests okay

TRIP Indication that a trip occurred

TIME Time-delayed trip

COMM Communications-assisted trip

87 Line current differential trip

50/51 Instantaneous and time-overcurrent trip

RECLOSERRSLO

Ready for reclose cycleControl in lockout state

FAULT TYPEA, B, CG

Phase(s) involved in faultGround involved in fault

ZONE/LEVEL1–3 Trip by Zone 1–3 distance elements and/or

Level 1–3 overcurrent elements

87CH FAIL Failure of active differential channel


18

Wiring Diagram

Figure 32 SEL-311L Inputs, Outputs, and Communications Ports

A19

A20

A21

A22

A23

A24

A25

A26

A27

A28

Z01

Z02

Z03

Z04

Z05

Z06

Z07

Z08

Z09

Z10

Z11

Z12

Z13

Z14

Z25

Z26

Z27

A17 A01

A02

A03

A04

A05

A06

A07

A08

A09

A10

A11

A12

A13

A14

A15

A16

OUT101

OUT102

OUT103

OUT104

OUT105

OUT106

OUT107*

ALARM

ISOLATEDEIA-485

PORT 1(REAR)

IRIG-B+ —

* OUT107 CAN OPERATE AS EXTRA ALARM

FRONT-PANEL TARGET LEDS

A18

IN101

IN102

IN103

IN104

IN105

IN106

PROG

RAM

MAB

LE O

PTOI

SOLA

TED

INPU

TSCU

RREN

T IN

PUTS

VOLT

AGE

INPU

TS

PROG

RAM

MAB

LE O

UTPU

T CO

NTAT

CS

JUM

PER

CONF

IGUR

ABLE

B01

B02

B04

B05

B07

B08

B09

B10

B12

B13

B15

B16

OUT201

OUT202

OUT203

OUT204

OUT205

OUT206

HIGH

-SPE

ED/H

IGH-

CURR

ENT

INTE

RRUP

TING

T CO

NTAC

TS

1 2 3 4 5 6 7 8

EIA-232 & IRIG-B

EIA-232

EIA-232

DB-9

DB-9

DB-9PORT 2 (REAR)

PORT 3 (REAR)

PORT F (FRONT)

CHASSISGROUND

BATTERYMONITOR

POWERSUPPLY

IA

IB

IC

IP

VA

VB

VC

N

VS

NS

TXRX

TXRX

One or two electrical or optical fiber differential channels

Single or dual redundant fiber-opticor copper 10/100 Mbps Ethernet ports


19

Front- and Rear-Panel Diagrams

Figure 33 SEL-311L Horizontal and Vertical Front-Panel Diagrams

4U Rack-Mount Horizontal Front Panel

3U Panel-Mount Horizontal Front Panel

3U Panel-Mount Vertical Front Panel

4U Panel-Mount Vertical Front Panel


20

Figure 34 SEL-311L Rear-Panel Diagrams Showing Differential Channel Options

Top

(for v

ertic

al m

ount

)To

p(fo

r ver

tical

mou

nt)

3U Rear Panel—Differential Channel Option With DB-25 Connector Outlined

4U Rear Panel—Differential Channel Option With Fiber-Optic Connectors

Differential Channel Option With DB-25 and Fiber-Optic Connectors

Differential Channel Option With 2 DB-25 Connectors

Differential Channel Option With 2 Fiber-Optic Connectors


21

Figure 35 Typical Rear-Panel Diagrams Showing Dual 10/100BASE-T and Dual 100BASE-FX Ethernet


22

Relay Dimensions

For projection rack mounting, brackets must be reversed.

Figure 36 SEL-311L Dimensions for Rack- and Panel-Mount Models


23

Specifications

ComplianceDesigned and manufactured under an ISO 9001 certified quality

management systemUL Listed to U.S. and Canadian safety standards (File E212775;

NRGU, NRGU7)CE MarkRCM MarkClass 1 Laser ProductNote: This equipment has been tested and found to comply with the

limits for a Class A digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his own expense.

General

Terminal Connections

Rear Screw-Terminal Tightening Torque:

Minimum: 9 in-lb (1.1 Nm)

Maximum: 12 in-lb (1.3 Nm)

Terminals or stranded copper wire. Ring terminals are recommended.Minimum temperature rating of 105°C.

AC Current Input

Nominal: 5 A

Continuous: 15 A, linear to 100 A symmetrical.

Thermal Rating: 500 A for 1 second.1250 A for 1 cycle.

Measurement Range: 0.5–96 A (DC offset for 1.5 cycles @ X/R = 10)

Burden: 0.27 VA at 5 A2.51 VA at 15 A

Nominal: 1 A

Continuous: 3 A, linear to 20 A symmetrical.

Thermal Rating: 100 A for 1 second.250 A for 1 cycle.

Measurement Range: 0.1–19.2 A (DC offset for 1.5 cycles @ X/R = 10)

Burden: 0.13 VA at 1 A1.31 VA at 3 A

AC Voltage Inputs

Nominal: 67 VL-N three-phase four-wire connection.

Continuous: 150 VL-N (connect any voltage up to 150 Vac).

Measurement Range: 365 Vac for 10 seconds.

Burden: 0.13 VA at 67 V0.45 VA at 120 V

Power Supply

Input Voltage

Rated: 125/250 Vdc or Vac

Range: 85–350 Vdc or 85–264 Vac

Rated: 48/125 Vdc or 125 Vac

Range: 38–200 Vdc or 85–140 Vac

Rated: 24/48 Vdc

Range: 18–60 Vdc polarity-dependent

Power Consumption: <25 W

Control Outputs

Standard

Make: 30 A

Carry: 6 A continuous carry at 70°C4 A continuous carry at 85°C

1 s Rating: 50 A

MOV Protection(maximum voltage): 270 Vac, 360 Vdc, 40 J

Pickup/Dropout Time: <5 ms

Breaking Capacity (10,000 operations):

48 Vdc 0.50 A L/R = 40 ms125 Vdc 0.30 A L/R = 40 ms250 Vdc 0.20 A L/R = 40 ms

Cyclic Capacity (2.5 cycles/second):


Hybrid (High Current Interrupting)

Make: 30 A


1 s Rating: 50 A

MOV Protection(maximum voltage): 330 Vdc, 130 J

Pickup/Dropout Time: <5 ms



Cyclic Capacity (4 interruptions/second, followed by 2 minutes idle for thermal dissipation):


Note: Make per IEEE C37.90-1989; Breaking and Cyclic Capacity per IEC 60255-23:1994.

Fast Hybrid (High Current Interrupting)

Make: 30 A


1 s Rating: 50 A

MOV Protection(maximum voltage): 330 Vdc, 130 J

Pickup/Dropout Time: <10 µs; <8 ms, typical




24

Cyclic Capacity (4 interruptions/second, followed by 2 minutes idle for thermal dissipation):


Note: Make per IEEE C37.90-1989; Breaking and Cyclic Capacity per IEC 60255-23:1994.

Optoisolated Inputs

250 Vdc: Pickup 200–300 Vdc; dropout 150 Vdc




48 Vdc: Pickup 38.4–60 Vdc; dropout 28.8 Vdc

24 Vdc: Pickup 15–30 Vdc

Note: 24, 48, 125, 220, and 250 Vdc optoisolated inputs draw approximately 5 mA of current; 110 Vdc inputs draw approximately 8 mA of current. All current ratings are at nominal input voltages.

Frequency and Rotation

System Frequency: 50 or 60 Hz

Phase Rotation: ABC or ACB

Frequency Tracking: 40.1–65 Hz

Serial Communications Ports

EIA-232: 1 Front, 2 Rear

EIA-485: 1 Rear, 2100 Vdc isolation

Baud Rate: 300–38400(Port 1 Baud Rate 300–19200)

Ethernet Communications Ports (SEL-311L-1 and SEL-311L-7)

Application Protocols

FTP to Card: 1 server session(supports IEC 61850 CID files)

Telnet to Card: 1 server session (supports SEL ASCII)

Telnet to Host: 1 server session (supports SEL ASCII, SEL Compressed ASCII, Fast Meter and Fast Operate)

IEC 61850: 6 MMS sessions16 incoming GOOSE messages8 outgoing GOOSE messages

Web Server: 3 simultaneous read-only server sessions to host

Protocol Stacks

TCP/IP

OSI

Physical Layer Options (PORT 5 and PORT 6)

10/100BASE-T: 10/100 Mbps, RJ45 connector

100BASE-FX: 100 Mbps, LC connector

Indicators (PORT 5 and PORT 6)

Link: Green LED is on when the link is operational.

Activity: Red LED blinks when there is transmit or receive activity.

Differential Communications Ports

Fiber Optics—ST Connector

1550 nm Single Mode:

Tx Power: –18 dBm

Rx Min. Sensitivity: –58 dBm

Rx Max. Sensitivity: 0 dBm

System Gain: 40 dB

Distance Limitations: 120 km

1300 nm Multimode or Single Mode:

Tx Power: –18 dBm

Rx Min. Sensitivity: –58 dBm


System Gain: 40 dB

Distance Limitations: x km

where: x = 30 for multimodex = 80 for single mode

1300 nm Single Mode (IEEE C37.94-Compatible Modulated):

Tx Power: –24 dBm

Rx Min. Sensitivity: –37.8 dBm


System Gain: 13.8 dB


850 nm Multimode, IEEE C37.94-Compatible:

Tx Power: 50 µm: –23 dBm; 62.5 µm: –19 dBm

Rx Min. Sensitivity: 50 µm: –32 dBm; 62.5 µm: –32 dBm

Rx Max. Sensitivity: 50 µm: –11 dBm; 62.5 µm: –11 dBm

System Gain: 50 µm: 9 dB; 62.5 µm: 13 dB


Electrical

EIA-422: 56 or 64 Kbps synchronous;Isolated to 1500 Vac

CCITT G.703: 64 Kbps synchronous, codirectional

Time-Code Input

Relay accepts demodulated IRIG-B time-code input at Port 1 or 2. Relay time is synchronized to within ±5 ms of time-source input.

Synchronization (specification is with respect to the accuracy of the time source)

Synchrophasor: ±10 μs

Other: ±5 ms

Current differential protection does not require an external time source.

Dimensions

Refer to Figure 36 for relay dimensions.

Operating Temperature

–40° to +85°C (–40° to +185°F)

Note: LCD contrast impaired for temperatures below –20°C

Weight

3U Rack Unit: 6.9 kilograms (15.2 pounds)

4U Rack Unit: 8.3 kilograms (18.3 pounds)

Type Tests

Electromagnetic Compatibility Emissions

EN 55011: 1998 + A1:1999 + A2:2002Canada ICES-001 (A) / NMB-001 (A)

Product Specific Emissions: IEC 60255-25:2000


25

Electromagnetic Compatibility Immunity

Conducted RF Immunity: IEC 60255-22-6:2001Severity Level: 10 Vrms

Radiated Radio Frequency Immunity:

IEC 60255-22-3:2007Severity Level: 10 V/m

IEC 61000-4-3:2010Severity Level: 10 V/m

Radiated Digital Radio Telephone RF Immunity:

ENV 50204:1995Severity Level: 10 V/m at 900 MHz and 1.89 GHz

Electrostatic Discharge Immunity:

IEC 60255-22-2:2008Severity Level: 2, 4, 6, 8 kV contact; 2, 4, 8, 15 kV air

IEEE C37.90.3-2001Severity Level: 2, 4, and 8 kV contact; 4, 8, and 15 kV air

Fast Transient/Burst Immunity:

IEC 60255-22-4:2008Severity Level: 4 kV, 5 kHz on power supply, 2 kV, 5 kHz on I/O, signal, data, and control lines

IEC 61000-4-4:2011Severity Level: 4 (4 kV on power supply), 3 (2 kV on inputs and outputs)

Power Supply Immunity: IEC 60255-11:2008

Radiated Radio Frequency Immunity:

IEEE C37.90.2-2004Severity Level: 35 V/m

Surge Withstand Capability Immunity:

IEC 60255-22-1:2007Severity Level: 2.5 kV peak common mode, 1.0 kV peak differential mode

IEEE C37.90.1-2002Severity Level: 2.5 kV oscillatory, 4 kV fast transient waveform

Environmental

Cold: IEC 60068-2-1:2007Severity Level: 16 hours at –40°C

Dry Heat: IEC 60068-2-2:2007Severity Level: 16 hours at +85°C

Damp Heat, Cyclic: IEC 60068-2-30:2005Severity Level: 25°C to 55°C, 6 cycles, Relative Humidity: 95%

Vibration: IEC 60255-21-3:1993Severity Level: Class 2 (Quake Response)

IEC 60255-21-1:1988Severity Level: Class 1–Endurance, Class 2–Response

IEC 60255-21-2:1988Severity Level: Class 1–Shock withstand, Bump, and Class 2–Shock Response

Safety

Product Safety: EN 50263:1999

IP Code: IEC 60529:2001 + CRGD:2003Severity Level: IP30 for Category 2 equipment

Insulation Coordination: IEC 60255-5:2000Severity Level: 5 kV Impulse on DI, DO, AI, and Power Supply; 2.2 kV on IRIG-B, EIA-485 and Ethernet.2.5 kVac Dielectric on DI, DO, and AI; 3.1 kVdc on Power Supply; 2.2 kVdc on EIA-485; 1.5 kVac on Ethernet. Type tested for 1 minute.

Laser Safety: IEC 60825-1:2007Product Class: Class 1

21 CFR 1040.10Product Class: Class 1

ANSI Z136.1-2007Product Class: Class 1

Product Safety: IEC 60255-6:1988

Processing Specifications

AC Voltage and Current Inputs

16 samples per power system cycle, 3 dB low-pass filter cut-off frequency of 560 Hz.

Digital Filtering

One-cycle full cosine after low-pass analog filtering. Net filtering (analog plus digital) rejects dc and all harmonics greater than the fundamental.

Current Differential Processing

16 times per power system cycle for line current differential protection and tripping logic.

Backup Protection and Control Processing

4 times per power system cycle

Relay Elements

Line Current Differential (87L) Elements

87L Enable Levels (Difference or Total Current)

Phase Setting Range: OFF, 1.00 to 10.00 A, 0.01 A steps

Negative-Sequence Setting Range: OFF, 0.50 to 5.00 A, 0.01 A steps

Zero-Sequence Setting Range: OFF, 0.50 to 5.00 A, 0.01 A steps

Accuracy: ±3% ±0.01 INOM

Restraint Characteristics

Outer Radius

Radius Range: 2 to 8 in steps of 0.1 (unitless).

Angle Range: 90–270° in steps of 1°

Accuracy: ±5% of radius setting±3° of angle setting

Operate Time(for bolted fault):

See operate time curves in Section 3 of the Instruction Manual.

Note: Refer to Current Differential Elements in Section 3 of the Instruction Manual for the definition of terms and terminology listed above.

Difference Current Alarm Setting

Setting Range: OFF, 0.5 to 10.0 A, 0.1 A steps

Accuracy: ±3% of ±0.01 INOM

Substation Battery Voltage Monitor Specifications

Pickup Range: 20–300 Vdc, 1 Vdc steps

Pickup Accuracy: ±2% ±2 Vdc of setting

Timer Specifications

Reclosing Relay Pickup: 0.00–999,999.00 cycles, 0.25-cycle steps (reclosing relay and some programmable timers)

Other Timers: 0.00–16,000.00 cycles, 0.25-cycle steps (some programmable and other various timers)

Pickup/DropoutAccuracy for All Timers: ±0.25 cycle and ±0.1% of setting


26

Mho Phase Distance Elements

Zones 1–4 Impedance Reach

Setting Range: OFF, 0.05 to 64.00 Ω secondary,0.01 Ω steps (5 A nominal)

OFF, 0.25 to 320.00 Ω secondary, 0.01 Ω steps (1 A nominal)

Note: Minimum sensitivity is controlled by the pickup of the supervising phase-to-phase overcurrent elements for each zone, load encroachment, OSB, and supervisory directional logic.

Accuracy: ±5% of setting at line anglefor 30 ≤ SIR ≤ 60

±3% of setting at line anglefor SIR <30

Transient Overreach: <5% of setting plus steady-state accuracy

Zones 1–4 Phase-to-Phase Current Fault Detectors (FD)

Setting Range: 0.5–170.0 AP-P secondary,0.01 A steps (5 A nominal)

0.1–34.0 AP-P secondary,0.01 A steps (1 A nominal)

Accuracy: ±0.05 A and ±3% of setting(5 A nominal)

±0.01 A and ±3% of setting(1 A nominal)

Transient Overreach: <5% of pickup

Max. Operating Time: See pickup and reset time curves in Section 4 of the Instruction Manual.

Mho and Quadrilateral Ground Distance Elements

Zones 1–4 Impedance Reach

Mho Element Reach: OFF, 0.05 to 64.00 Ω secondary,0.01 Ω steps (5 A nominal)


Quadrilateral Reactance Reach:

OFF, 0.05 to 64.00 Ω secondary,0.01 Ω steps (5 A nominal)


Quadrilateral Resistance Reach:

OFF, 0.05 to 50.00 Ω secondary,0.01 Ω steps (5 A nominal)


Note: Minimum sensitivity is controlled by the pickup of the supervising phase and residual overcurrent elements for each zone, and supervisory directional logic.

Accuracy: ±5% of setting at line anglefor 30 ≤ SIR ≤ 60

±3% of setting at line anglefor SIR <30

Transient Overreach: <5% of setting plus steady-state accuracy

Zones 1–4 Phase and Residual Current Fault Detectors (FD)

Setting Range: 0.5–100.0 A secondary,0.01 A steps (5 A nominal)

0.1–20.0 A secondary,0.01 A steps (1 A nominal)

Accuracy: ±0.05 A and ±3% of setting(5 A nominal)




Undervoltage and Overvoltage Elements

Pickup Range: OFF, 0.00–150.00 V, 0.01 V steps(various elements)

OFF, 0.00–260.00 V, 0.01 V steps(phase-to-phase elements)

Steady-State Pickup Accuracy: ±1 V and ±5% of setting

Transient Overreach <5% of pickup

Instantaneous/Definite-Time Overcurrent Elements

Pickup Range: OFF, 0.25–100.00 A, 0.01 A steps(5 A nominal)

OFF, 0.05–20.00 A, 0.01 A steps(1 A nominal)

Steady-State Pickup Accuracy:

±0.05 A and ±3% of setting (5 A nominal)



Time Delay: 0.00–16,000.00 cycles, 0.25-cycle steps

Timer Accuracy: ±0.25 cycle and ±0.1% of setting


Time-Overcurrent Elements

Pickup Range: OFF, 0.25–16.00 A, 0.01 A steps(5 A nominal)

OFF, 0.05–3.20 A, 0.01 A steps(1 A nominal)

Steady-State Pickup Accuracy:



Time Dial Range: 0.50–15.00, 0.01 steps (US)0.05–1.00, 0.01 steps (IEC)

Curve Timing Accuracy: ±1.50 cycles and ±4% of curve time for current between 2 and 30 multiples of pickup.

Synchronism-Check Elements

Slip Frequency Pickup Range: 0.005–0.500 Hz, 0.001 Hz steps

Slip Frequency Pickup Accuracy: ±0.003 Hz

Phase Angle Range: 0–80°, 1° steps

Phase Angle Accuracy: ±4°

Definite-Time Overfrequency or Underfrequency (81) Elements

Pickup Range: 41.00–65.00 Hz, 0.01 Hz steps

Pickup Time: 32 ms at 60 Hz (max)

Time Delays: 2.00–16,000.00 cycles, 0.25-cycle steps

Maximum Definite-Time Delay Accuracy: ±0.25 cycles, ±1% of setting at 60 Hz

Steady-State plus Transient Overshoot: ±0.01 Hz

Supervisory 27: 20.0–150.0 V, ±5%, ±0.1 V


27

Metering AccuracyVoltages

VA, VB,VC, VS,V1, V2, 3V0: ±2% (33.5–150 V)

Currents

IA, IB, IC, IP (Local): ±1% (0.5 to 100.0 A) (5 A nominal)±1% (0.1 to 20.0 A) (1 A nominal)

I1,3 I0, 3I2 (Local): ±3% (0.25 to 100.0 A) (5 A nominal)±3% (0.05 to 20.0 A) (1 A nominal)

IA, IB, IC, 3I2, 3I0, I1 (Remote):

±3% (0.25 to 100.0 A) (5 A nominal)±3% (0.05 to 20.0 A) (1 A nominal)

IA, IB, IC, 3I2, 3I0, I1 (Total):

±3% (0.25 to 100.0 A) (5 A nominal)±3% (0.05 to 20.0 A) (1 A nominal)

Phase Angle Accuracy: ±1°

MW/MVAR: ±3%

Synchrophasor AccuracyNote: Specification is with respect to MET PM command and SEL

Fast Message Synchrophasor Protocol.

Voltages: 33.5–150 V; 45–65 Hz

Magnitudes: ±2%

Angles: ±1.0°

Currents: 0.50–1.25 A; 45–65 Hz (5 A nominal)0.10–0.25 A; 45–65 Hz (1 A nominal)

Magnitudes: ±4%

Angles: ±1.5° @ 25°C±2.0° over the full temperature range

Currents: 1.25–7.50 A; 45–65 Hz (5 A nominal)0.25–2.50 A; 45–65 Hz (1 A nominal)

Magnitudes: ±2%

Angles: ±1.0° @ 25°C±1.5° over the full temperature range

28

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The information in this document is provided for informational use only and is subject tochange without notice. Schweitzer Engineering Laboratories, Inc. has approved only theEnglish language document.

This product is covered by the standard SEL 10-year warranty. For warranty details, visitselinc.com or contact your customer service representative. *PDS311L-01*

2350 NE Hopkins Court • Pullman, WA 99163-5603 U.S.A.Tel: +1.509.332.1890 • Fax: +1.509.332.7990selinc.com • [email protected]

SEL-311L Data Sheet Date Code 20211203

Technical Support

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